ARCHIVELOG to NOARCHIVELOG Mode Comparison

Installing the Agent › Perform Post-Installation Tasks › ARCHIVELOG to NOARCHIVELOG Mode Comparison

ARCHIVELOG to NOARCHIVELOG Mode Comparison

The following table explains the advantages and disadvantages of ARCHIVELOG mode and NOARCHIVELOG mode.

Mode	Advantages	Disadvantages
ARCHIVELOG mode	You can perform hot backups (backups when the database is online). The archive logs and the last full backup (offline or online) or an older backup can completely recover the database without losing any data because all changes made in the database are stored in the log file.	It requires additional disk space to store archived log files. However, the agent offers the option to purge the logs after they have been backed up, giving you the opportunity to free disk space if you need it.
NOARCHIVELOG mode	It requires no additional disk space to store archived log files.	If you must recover a database, you can only restore the last full offline backup. As a result, any changes made to the database after the last full offline backup are lost. Database downtime is significant because you cannot back up the database online. This limitation becomes a very serious consideration for large databases.

Mode

Advantages

Disadvantages

ARCHIVELOG mode

You can perform hot backups (backups when the database is online).

The archive logs and the last full backup (offline or online) or an older backup can completely recover the database without losing any data because all changes made in the database are stored in the log file.

It requires additional disk space to store archived log files. However, the agent offers the option to purge the logs after they have been backed up, giving you the opportunity to free disk space if you need it.

NOARCHIVELOG mode

It requires no additional disk space to store archived log files.

If you must recover a database, you can only restore the last full offline backup. As a result, any changes made to the database after the last full offline backup are lost.

Database downtime is significant because you cannot back up the database online. This limitation becomes a very serious consideration for large databases.

Important! Because NOARCHIVELOG mode does not guarantee Oracle database recovery if there is a disaster, the Agent for Oracle does not support this mode. If you need to maintain Oracle Server in NOARCHIVELOG mode, then you must backup full Oracle database files without the agent using Arcserve Backup while the database is offline to ensure disaster recovery.

When you are working with RMAN, ensure that the database runs in ARCHIVELOG mode.